Apparatus for electrical treatment of gases



Dec. 25', 1923. 1,478,798

. v A. SCHMIDT- APPARATUS FOR ELECTRICAL TREATMENT OF tinsss Filed May27. 1919 2 Sheets-Sheet 1 IN VEN TOR diam/2,141

A TTOHNE V ecu 259 A A sCHMlDT APPARATUS FOR' ELECTRICAL TREATMENT OFGASES Filed May 27 191.9 2 Sheets-Sheet 2 A TTORNEY of 2-2, Fig. 4;

Patented Dec. 25,1923.

UNITED STATES PATENT orrics.

ARTHUR A.-'1, OF LOS ANGELFS, CALIFORNIA, ASSIGHOB '10 INTERNATIONALPBEIPITATIOH COMPANY, LOS ANGELEs, CALIFORNIA, A GORPOEATIOR" 0]CALIFORNIA.

APPARATUS FOR ELEOTBIOAlZ 133mm 0! Application on my 27, 1919. SerialNo. accuse.

To all whom it may concern:

Be it known that I, Aurnun A. Sonnm'r, a citizen of the United States,residing at Los Angeles, in the county of Los Angeles and .State ofCalifornia, have invented a new and useful Apparatus for ElectricalTreatment of Gases, of which the following is the specification.

This invention relates to the art of separato tion of suspendedparticles such as smoke, fume, etc-., from furnace gases, or othergases, by the action of an electric field. In such apparatus the gas tobe treated is passed between suitable electrodes between which a highpotential difierence is maintained, under such conditions that thematerial suspended in the gases is caused to be precipitated on certainof such electrodes, usually referred to as collecting or receivingelectrodes. Such collectin or receiving electrodes in apparatus 0% thischaracter are generally constituted by the walls of the chambers orpassages through which the gas is conducted. The main object of theprescut invention is to provide anelectrical precipitator of improvedconstruction wherein the walls constituting the collecting electrodesare constructed in such manner as to provide a maximum collectingsurface for a given size treater. A further object of the invention isto fprovide improved means for equalizing the ow of the gases throughthe multiplicity of' passages in. the electrical precipitator. v

88 Another obtiect of the invention is to provide improve means forremoving the re? cipitated material from the walls or sur acesconstituting the collecting electrodes.

' l The accompanyi drawings illustrate.

embodiment of my invention, and referring .thereto:

Fig. 1 is a vertical section of the apparatus taken on line 1-1, Fig. 4.Fig. 2 is a vertical section taken on'line Fig. 3 1s 'a-horizonta'lsection taken on line 3-3, F lg. 2. i 4

Fig. 4 isa horizontal section taken on line 4-4,.I i 2.

5 is a vertical section of one of the cleaning brushes.

Fig. '6 is a side elevation and Fig. 7 an end.

elevation of a, plurality of hunters provided municate wit able mannerand are pre with means for automatic operation of same in cyclic orderfor precipitation and for removal of the precipitate.

Fig. 8 is a partly sectional side elevation and ig. 9 an end elevationof one of the valve devices for controlling such c clic operation, saidFig. 9 being taken on line 99,

Fig. 6.

- he apparatus shown comprises an outer casing it having vertical walls1, a closed top ,2, and a hopper shaped bottom 3, provided with suitablemeans such its gate a for re moving collected material. A horizontalpartition 5 extends across the outer casing to orm a top header orchamber 6 into which \-opens a conduit 8 for conducting the gas to orfrom the apparatus. Another conduit .0; fine 9 leads fromthe lower partof the c In the following description the gases be assumed to enter atthe upper conduit 8 and be discharged through the lower conduit 9, butthe direction of the gas stream may he reversed if desired. The outercasing 1 may be mounted on suitable supporting columns 10. v

Aplurality of vertical gas receiving flues 12 are mounted in connectionwith the transverse horizontal partition 5, aforesaid,said flues beingoen at their lower ends to comli the space 13 at the lowergart of casing.11. and open at their up er en to communicate with the upper he er 6.For the sake of compactness, I prefer to form, these vertical lines ofhexagonal shape, as shown in Fig. 4, assembled in close order in suchmanner as" to give a cellular or reticulate construction similar to thatof a honeycomb structure. The walls of these hex-- agonal fines may beformed of 'sheet metaland may be fastened to ther in any sultrablyconnected at .their upper and lower ends to frames 14 and 15 formounting thesaine. If-desired, these flue's may be formed in apluralityof sections 0 and d, separated as indicated at 16. These collectingelectrodes or flues rnay ri 'dly mounted in statibnarypo'srtxon in ca?0, but tofacilitste cleann g the same 1' pre er to mount the said timein such mam.

'. nor" as to enable them to .be raised or lowered as hereinafterdescribed; The hopper or mceptacle 3 is permanently connected below thesaid fallingfromthesaidwhuherat thetimesofcleaningoratothertinmwillfall'into said receptacle Discharge electrodes 20extend vertically andaxially in the respective lines 12, said dischal' electrodm consisting,for example,

ofm 'cwiresorrodsofsmtablefineness to 't electriull therefrom at thepotential difference under which the apparatus is to be operated-raiddischarge electrodes being held rigidly, behveen upper insulator framebars or beams 22 and lower insulator frame bars 23, connected to theupperand lower ends of the discharge electrodes. The supporting'bars'22and 23 are mounted on suitable insulators 27 and 28 which are secured infixed position in suitaing arranged in rows or sets above the re--spective sets and (d) of Hum. The said sets of fines (a) and ((1),together with their upper and lower frames 14 and 15, and.

vertical connecting bars 25, constitute a rigid body, which is guidedvertically by guide rollers or wheels 32 on which run the verticali'rsme bars 25. Any suitable'lneans may he provided for raising thecollecting I electrode system to efiect the cleaning theretill so, fromwhi nected to a wire 43 leading to anysuitabloj of, tier example, ahydraulic ram comprising a cylinder 34 and a plunger 35, connected bycable 38 r g on sheaves 3910 a frame epend bars 37 connected to therespective cs 14 and 15, so as to hit the collecting electrode bodily bythe action of the hydraulic ram. Brushes 31 may be form@ in annular orpolygonal shape to fit the walls of" the collectin electrode tines andare mounted on spi em or open as 31?, so as to permit p of gas throughsame and also, in case of the lower brushes, to permit of theprecipitated matenal p downwardly through the brushes in cl 1 collectingelectrode system is normally supported on cross-beams 40 on which thelower frame rests and a horizontal extension plate constituting'thetransverse horizontal partition aforesaid is attached to the upper frame14 and norinall extends directly over 42 on the weld of easing 1.discharge electrode system is cdnsource of current, for example,saidwire may be so phed with currentin the manner set forth in patent toF. G. Cottrell, No. 895,729, August 11th, 1908 in such manner of theapparatus. The

as to maintain a unidirectional high potential difi'erence between thedischarge electrodes and the collect electrode lines 12, the latterbeing un ed and the current being completed t lrough groundedconnections at the source of current.

I prefer to provide for automatically cutting oil? the electric currentsupply and also the supply of gas to the apparatus during valves ordampers 51. and 52 are provided at the inlet flue or conduct 8 andoutlet flue or conduct 9 of the apparatus and are connected to levers 53engaged by frame 36 to close the dampers when said frame is raised andto'open the dampers when the frame is lowered to normal position. Thecleaning operation may be performed intermittently or periodically "bytime controlled mechanism, and, in case of a plurality of precipitatorsin a single installation, I prefer to provide for successive cleaningoperations in the several precipitators -in cyclic manner. Suitablemeans ion this purpose is shown in Figs. 6 to 9, comprising a.pluralityot valves 55, 56, 57 and 58, connected by pipes 59 to ramcylinders 34 for the respective precipitators, and operated by cams 61,62, 63, and 64, respectively, v

carried by a shaft 65, which is rotated at low speed by gearin 66operated by motor 57. Each of said va vcs, when operatedby thecorresponding cam, opens connection from a water pressure supply pipe 68to the corresponding pipe 59 and when the valve is returned to normalposition by a spring 69, it opens connection from said pipe 59 to outletpipe 70, to allow the ram plunger to return to normal position. The cams61, 62, etc, are angularly displaced around shaft 65 so as to causesuccessive operation of'valves 55, etc., and operation in cyll order ofthe cleaning means for the several precipitators, so that theprecipitators are cleaned one at a time.

The operating of the apparatus is as fol-- lows 4 The gas to be treatedis supplied, for ex ample, through flue 8 and passeskdownwa wardlythrough the successive sections b and c of the collecting electrodefines and then out'throu h flue 9. Normally'the collectingelectr esystem is supported on the supporting I beams 40 with the upper plate 5extending from frame 14 resting on or' lying directly over flanges 42 onthe enclosmgcasmg 1 so as to cause all of the gas to Ell n t-1am bedirected through-the collecting-electrode fines. A suitable highpotentialdiflerence, say 50,000 volts or over, is maintained between thedischarge electrodes 20 and the collecting electrode lines 12- and thesuspended material or suspended; particles are precipitated on the wallsof the collectin electrode flues by the action of the ectrical field soproduced, in such manner that .the gases which pass out through theoutlet 9 are comparatively clean or free of suspended material. An imortant advantage of the construction described wherein the collectingelectrode flues are made in a plurality of sections with open spacesbetween is that better equalization or distribution of the gases issecured between the parallel fines. Inapparatus of this kind including amultiplicity of parallel lines there is generally a tendency for thegases 0 the I to flow more rapidly through some fines than others,either on account of unequal heat distribution, resulting in difierencein density or buoyancy of the gases, or on account of disturbances due,for example, to outside influences, such as wind or at'- mospher'iccurrents; these disturbing or unf the length equalizin influencesgenerally increase with of the vertical lines and by dii ing thefiues ina plurality oi'sections opportunity is given for the gases to equal-'ize themselves as regards velocity, pressure. and temperature betweenthe several flues;

' The material deposited or precipitated on the walls of the-collectiugelectrode flues maybe removed continuously or from time to tim by anysuitable means. With the construction shown in the drawing, such removalis conveniently efiected by raising the entire collecting electrodesystem bodily at stated or required intervals by operation of therein34, or otherwise, causing each section of theelectrode dues to be drawnup past the brushes 31 in such manner that the precipitated material isbrushed .or dis lodged fromthe walls of the lines and descends bygravity to the bottom of the treatthe cleaning operation 'is being er.To facilitate this operation, it is preferable to cut off the supply ofcurrent'while performed and the draft may also be out Q or reduced atsuch time. In..this connection, it. is-to be noted that the introductionofthe brushes within the respective collecting electrode fines tends ofitself to diminish the effective cross-section of the lines as regardspassage of the gases therethrough so that the draft 1 through the inletand outlet pipes will be automatically reduced during the cleaninqgoperation, the brushes. acting as parti dampers in the fines and thenagain on lo ering thecollect ng electrode system the cleaningoperationis repeated and the sys-' tem finally comesto rest in normalposition,-be ng.then supported on the beams 40.

I prefer, however, to also. provide ositive dampers, as shown at 51 and52 at t e inlet and outlet, or both, and to operate said dampersconcurrently with the cleaning etc., are operated successively by thecams 61, etc., to cause succemive operation of the cleaning means forthe respective precipita-. tors an correspond precipitator by opemnswitch 50 an to stop the gas flow throng to the prccipitator, c osingvalves 51 and 52 soas' to shut ofi' communication .with inlet flue'Z3'and outletflue 74. v This provides for automatic and periodiccontrol of the cleaning means and for shutting oil of thogas stream andof the electric current durin the cleaning, and the expense of mannacontrol is thereby obviated and it is thereby rendered practicabletoefiect cleaning at short intervals, (say of a few minutes duration),and to thereby keep the collecting electrodes in relatively cleancondition. This contributes materially to efiiciency of precipitation,as electrical precipitation is ar more effective when the collectingelectrade is substantially clean than when a doalso to cut oil thecurrent to the positof considerable thickness has been 7 proximateuniformity of electric field and maximum effective precipitatingcapacity for each flue, together with complete utili 7 zation of thetreater spaces and elimination of waste spaces such as are generallyfound in the ordinary round pipe treaters by reason of the pipes.

While the above described apparatus is intended particularl forelectrical precipitation of suspende necessary separation of thematerial from gases,

some oi the -fatures of the invention, particularly,,the hexagonalcellular electrode flue system and the arrangement 1 of the electrode'flue' system in a plurality of 8110- i cessively acting sections spacedapart to permit equalization of the gases, are applicable enerally toelectrical treatment of gases or various cal reactm r Animportant'feature of-the present in v vention, as applied toelectrical-precipitation, is the provisionior removing the -de-' positfrom the collecting means such as brushes, which are normally removedfrom the said electrodes so as not purposes, such as electro-chemielectrodes by to interfere with tions 0 plrec'i itation and to leave theprecipitation 0 am rs free for effective (iperation throughout thecollecting surfaces.

I; will be understood that the term brush ing means, as used herein,includes any suit ab e means for brushing,'scraping orotherwisepositively removing the deposit from the collecting electrodes. It willalso be un derstood that the relative motion of the brushing means andthe collecting electrode means required for the cleaning operation mayefiected by moving either of such means. Thus, for example, thedischarge electrode system may be mounted to move relatively to thecollecting electrodes to bring the brushes into operative relation forcleaning and, preferably, at the same time, to open the circuitconnection to the supply circuit, substantially as above described-forthe collecting electrode system.

What Iclaim is:' e

1; In an apparatus for the electrical treatment of gases, a plurality ofparallel discharg electrodes and a plurality of seccollectingelectrodes, each section of collecting electrodes comprising a pluralityof parallel fines respectively surrounding said discharge electrodes,and said s'ections bein spaced apart to permit interflow and e uahzationof the gases between the-= 7 severe flues of the sections, and means forconducting the gases to and from the said collecting electrodes. 2. .Inan apparatus for the electrical precipitation of suspended material fromgases the combination of a plurality of vertica discharge electrodes anda collecting electrode system, comprising a plurality of sections, eachsection consisting of a plurality of vertical collecting electrodefluessurrounding the respective discharge electrodes, said sectionsbeing spaced apart vertically, means for conducting gases to one of sa dsections, and means for conducting gases Y away from another of saidsections, whereby the gasis caused ,to pass successively through saidsections andtobe equalized between the diiferent flues of each section;

3. Inan apparatusfor the electrical'precipitation of suspended' materialfrom gases, the combination of a vertically extending dischargeelectrode, a vertically extending collecting electrode tzpposingthe Isame, brushing means moun in xed position adjacent to vaaidcollectelectrode, means 'for reciprocating said col ecting electrode in avertical path to cause it to be brought into.

' contact with'said brushing means orout of contact therewith anda'receptacl'e permanently located below said collecting electrodes toreceive the precipitated material removed therefrom.

4.- In an .apparatus for the electricalprecipitation'ofsuspendedmaterial from gases he combination of a'verticglly extending dischargeelectrode, a collecting electrode extending vertically opposite thedischarge electrode, cleanin means mounted on said discharge electrodefor removing preci itated material from said collectin electrode, andmeans for reciprocating sai collecting electrode adjacentvto saidcleaning means to cause cleaning of the electrode by said cleaningmeans.

'5. The combination of an electrical precipitator comprising electrodesand .means for supplying said electrodes with high tension current, soas to maintain the -electrodes at high potential difference; means forcleaning the electrodes; means for periodically operating said cleaningmeans, and switch means for controlling supply of' current to theelectrical precip1tator,and means automatically operative to maintainsaid switch open during the operation of the cleaning means.

6. The combination of a collecting electrode,"a discharge electrode,cleanin means for the collecting electrode, means or periodi callyoperating said cleaning means, and

'maticallyso as to be open during the cleanin operation, i I I In anapparatus for the electrical precipitation of suspended material from.gases,

'electrode means for effecting electrical action on the s to precipitatesuspended particles there rom, a conduit for conducting the gas to-.betreated between said electrode means, damper means controlling the fl owof gas in said conduit, automatic cleaning means for the removal of. theprecipitated material from the collecting electrodes, periodicallyoperating means for controlling the operation of said cleaning means atdefinite intervals and means for efiectin operation of said damper meanssimu taneously with said cleaning means at? shut off the flow ofgasduring the cleaning oper ation.

8. In an apparatus for the electrical precipitation of suspendedmaterial from gases, a" plurality offe ectrical precipitation units,each provided with automatically operated electrode" cleaning means 'forremovln the reci itated material, conduits for con mi:-

ing t e gas to be treated to the respective electrical precipitationunits, periodically operating means controlling the operation of saidautomatic'cleanin' mean's successiv'ely for the'respective e ectricalrecipimeans for operating the'damper means for the conduit leading toeach'electrical pron cipitation unit simultaneously with'the op eration.of the cleaning ,means for such un t.

9. In an apparatus for removing 8- ggnded particles from gaseous andfluid flow dies, the combination with a stationary discharge electrodeand a reciprocable collecting electrode of means arranged to con- 6'tact with the collecting surface of said last .named electrode to scrapesaid surface when said electrode'isreciprocated. v

'- 10. In an apparatus for removing suspended particles from gaseous andfluid flow l0 bodies, the combination with a stationary contact with theinner periphery of said c ollecting electrode to scrape the same whensaid electrode is reciprocated.v

In testimony whereof I have hereunto subscribed my name this 20th day ofMay, 1919;

ARTHUR A. SCHMIDT.

